Hammer head



FIG. 1 is a perspective illustration of an embodiment of the hammer head according to my design;

FIG. 2 is a right side view thereof, the left side being a mirror image thereof;

FIG. 3 is a front plan view thereof;

FIG. 4 is a rear plan view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof.

The broken lines in FIGS. 1 through 6 illustrate environmental structure that forms no part of the claimed design. 

The ornamental design for a hammer head, as shown and described. 